This is the lowest value recorded during the current performance-monitoring interval of the polarization-dependent loss (PDL) measured on this channel during the current performance-monitoring interval, expressed in dB, reflecting how much the signal's loss varies depending on its polarization state as it passes through the optical path. The lowest PDL seen in the interval shows how good the path gets, useful for confirming the baseline PDL contributed by the fixed optical components in the path. For example, a well-maintained ROADM node would show polarizationDependentLossMin staying near the sum of its components' rated PDL specifications, with little added by degraded parts.